Bootstrap, from Twitter

Bootstrap is a toolkit from Twitter designed to kickstart development of webapps and sites.
It includes base CSS and HTML for typography, forms, buttons, tables, grids, navigation, and more.

Nerd alert: Bootstrap is built with Less and was designed to work out of the gate with modern browsers in mind.

Media Displaying images and videos

Media grid

Display thumbnails of varying sizes on pages with a low HTML footprint and minimal styles.

Example thumbnails

Thumbnails in the .media-grid can be any size, but they work best when mapped directly to the built-in Bootstrap grid system. Image widths like 90, 210, and 330 combine with a few pixels of padding to equal the .span2, .span4, and .span6 column sizes.

Large

Medium

Small

Coding them

Media grids are easy to use and rather simple on the markup side. Their dimensions are purely based on the size of the images included.